Bill Tomlinson

My battery discharged over a two day period. I found a couple of problems and fixed them.

I did have a .85 amp drain. It is now down to .16 amp.

What is normal? My truck is an early '91 and has minimal electronics.

I may be facing battery replacement as I am on my third year with a slightly undersized unit. I would like to eliminate any problems BEFORE I buy a heavy duty unit and risk ruining it.

RuralCruiser007

The rating for max draw of a vehicle is 0.050 amps. You are still a little high.

Check for a bulb being on, like the glove box lite. You are looking for something small being on. I am thinking a 194 bulb. That is why I am thinking your glove box lite.

In our vehicles we have dont have a bunch of computers that we have to wait to "go to sleep".

With new technology, we also have the remember satalite radios. If you have it plugged in but off it will still be drawing. Have it unplugged when you are testing.

Bill Tomlinson

That's what I wanted to know. I will keep on looking. I know about the glove box light, it got me once so I removed it. I will check each fuse terminal and see if I can find a leak. I wonder if a relay somewhere could be dying? I just did not want to keep searching if the draw was close to normal but apparently it is not. Thanks for the data.

Jim Lane

You probably already checked this but a battery with a dirty top can discharge itself quickly.

Hood lights have a habit of staying on especially if you are parked on an incline like in your driveway.

Glove box light like he mentioned, mine is always coming on because the door gets warped after all of the years.

If you have a brake controller and park on an incline an out of adjustment inertia control can cause the brake lights to come on.

Also a wet trailer connector can draw current.

Bill Tomlinson

Thanks for the info. I have some interesting wiring. My battery is spotless, but I know what some of them look like. I get such a steady discharge reading, always .16 amp measured between the ground strap and the ground terminal on the battery that I don't suspect the trailer wiring. I will give it a going over anyway. Hmm. It has been wet. Leakage might be steady if it were due to moisture.

The brake controller is another thing worth looking at. My brake lights don't stay on. My drive way is rather steep but it happens even when I park on the level. Brake lights would discharge more than the .16 amp.

I think I should spend some time cleaning up loose wires, eliminating old, unused stuff. I did wire in a line for an aux fan I no longer use. Must check all of that stuff. Meanwhile I undo the ground when I park.

Keep the ideas flowing guys.

RuralCruiser007

Just for giggles, clean the battery cables and ground connections.

The hidden green monster could be lurking in them.

You never know where the problem could be.

Good luck!

rockfoot

Your radio have a clock? Is your alternator warm? Like you said... start pulling fuses till it goes away....

Bill Tomlinson

One of the things which reduced the drain was disconnecting the radio. It's rom chip went haywire and the ignition lead and backup lead went weird. Connecting the ignition switched wire does nothing. Connecting the backup always hot lead keeps the radio on all the time. No, they are not connected wrongly, the problem is due to some interior problem with the radio.

The alternator thing is possible. After unhooking the radio, I checked every fuse for current and found no suspicious drains there, yet a continuous .16 amp at the battery. I have a couple of things to check out first and then I will have a real good look at the alternator. I wonder if a bad diode could cause a leak?

rockfoot

no... not normally... what would cause the leak would be a bad voltage regulator... it continues to feed the field after the ignition is turned off....

Bill Tomlinson

Well, I'll change that and see. I have a half dozen old mopar regulators and one of them might change things.

Thanks for the ideas. Nothing worse than staring at a bunch of wires and scratching one's head

jimlj

I was having the same problem with one of my work trucks. The mechanic sent the alternaror to have it tested/repaired. When it came back the problem was cured. I don't know what was done to it though.

mobill228

If you have a seatbelt warning, check for a seatbelt relay. Mine was under the center console of the seat. It went bad and caused my truck to do the same thing. Went to a junk yard, purchased one and cured the problem.

BearKiller

I spliced a toggle-switch in the wire to the hoodlight on the son's truck, and intend to do all the rest of them likewise.

With the switch ON, the hood-light still functions the same; but now, he can turn off the switch and leave the hood up, without the light being on.


To actually be of any benefit, it should really have about six 100-watt bulbs, strategically located, instead of one little dim bulb over there on the wrong side of things.

BILL, I figure your battery drain is gonna wind up being either the alternator or regulator.

We had an alternator short-out on a tractor and burn the insulation off every wire, before I could get the grille out and the battery cable off.

Bill Tomlinson

I suspect the alternator. I will check it asap. Thanks.

There have been some suspicious voltage readings. Way too high and now just basic 14 volts no matter how discharged the battery is. It won't hurt to have it tested.

The good ideas just keep coming in and about half of them involve something which has already happened in the past.

RuralCruiser007

Now one to look for is overcharging! My truck Moose was overcharging to beat the ban off idle. Put a new voltage regulator in it and still no difference.

I took my time and looked at the wiring diagram. Found with my search of my diag that if there is low voltage to the regulator, then overcharge. Sourced the basics of the problem to a corroded terminal at the voltage regulator. This is the bue wire into the voltage regulator.

Took me three times till I got the terminal clean. Finally used a chainsaw file.

HTH